EFFECTS OF DIFFERENT CYTOPLASMS ON QUANTITATIVE CHARACTERS

IN MAIZE

Voichita Has, I. Has

Agricultural Research Station, Turda,

 Agriculturii 27 Street, P.C. 401100, Turda, Romania

tel. +40-264-311680; fax +40-264-311792;

E-mail:  hasvoichita@yahoo.com

            The study of cytoplasmic effects on the expression of quantitative characters is important in learning about cytoplasmic-nuclear interactions and their influence on breeding and genetic programs. The genotypes of six early-time maize inbreds T 248, TC 243, TC 209, TB 367, A654, TC 102, T 291 were backcrossed eight times into ten cytoplasms other than their own. Thus, each cytoplasmic source of seed was assumed to have the same nuclear genotype. Five characters were studied over two years and two locations. Significant differences among the cytoplasms occurred for plant vigor, date of tasseling and silking, stalk lodging resistance and kernel dry matter.

Table 1 Mean percent of stalk lodging resistance at harvest for each of the ten cytoplamic sources with six genotypes

Pair

no.

Inbred genotype

TC 209

T 291

T 248

TC 243

TB 367

TC 102

Cytoplasmic source

%

%

%

%

%

%

1.

Own cytoplasm

61.1

32.6

68.6

68.0

66.1

42.6

2.

T 291

61.0

x

71.4

60.8

70.2

  53.8**

3.

T 248

61.3

    49.9**

x

68.8

69.6

59.1***

4.

TC 243

55.0

30.7

66.4

x

  72.1*

58.9***

5.

A 654    

61.3

    56.7***

70.9

60.2

71.5

59.0***

6.

TC 221

61.5

35.5

66.8

63.5

63.3

55.8**

7.

TC 102

55.4

41.4

67.1

69.9

70.5

x

8.

TC 209

x

    56.6***

69.0

65.5

71.4

44.2

9.

K 1080

58.3

40.2

68.3

62.8

62.5

48.3

10.

TC 316

60.2

30.7

  58.800

64.7

   74.9**

40.4

 

LSD  5%

9.0

9.9

7.0

10.7

5.8

7.9

 

         1%

12.0

13.4

9.4

14.6

7.8

10.7

 

       0,1%

15.8

17.7

12.4

19.5

10.3

14.1

Differences in grain yield among cytoplasms were not significant, or their expression was of low magnitude, probably they have been modified by interaction with environments. Differences that did exist were in the direction expected on the basis of inbred performance. The results indicated that differences in performance of the inbreds were not necessarily an indication of cytoplasmic effects in hybrid combination. Results from these experiments provide further support for cytoplasmic effects on some agronomic characters in maize. They also emphasize that the environment can influence the performance of cytoplasm from one year to another.